Downing Street has raised the target for volunteers to help vulnerable people through the coronavirus crisis to 750,000 after more than half a million responded to the call.

The Government launched an appeal on Tuesday for 250,000 people to help those self-isolating for the next 12 weeks – but more than double the number had signed up two days later.

People are being sought to help deliver shopping and medication to those in need, transport patients and NHS equipment, or check in and chat on the phone with individuals at risk of loneliness as a result of self-isolation.

Despite the threshold being met twice over – with 560,000 people volunteering by Thursday morning – the Prime Minister’s official spokesman said the scheme would stay open.

He told a Westminster briefing: “I think the most recent number I’ve seen was around 560,000 people who have volunteered so far which is amazing – but we want people to continue to volunteer and if we can reach a number of 750,000 then that would be fantastic.”

Volunteers who have already signed up to help the health service have shared their reasons for joining the cause.

Stuart Beards, 26, hopes to be able to offer support by driving and taking deliveries, and said he was motivated by “the countless pleas online from health officials to support the NHS”.

He said: “It needs to be a universal community effort to support the NHS.”

When asked about any concerns for his own health, the London-based security operations manager told the PA news agency he was “already taking precautions at home and are sticking to the rules implemented by the Government and health advice to minimise any contact”.

He added: “At the end of the day, if we can help by volunteering, it may stop a vulnerable person leaving their home.

“If it helps keep one person safe, it’s worth it.”

Lisa O’Hare said she has been saved by the NHS in the past (Lisa O’Hare)

Lisa O’Hare, 44, from Wilmslow, has also signed up and wants to give back to the health service that has helped her.

“I’ve got one dodgy kidney but I wouldn’t like the other to be fighting on its own,” she said.

“If it wasn’t for the NHS, I wouldn’t be here now. They’ve saved me and so many people I love so many times. This is the least I can do.”

The tax manager will be making calls to vulnerable people as she has an underlying health condition and does not wish to risk potentially exposing herself to the virus.

She added: “It felt like something I could do from my house which is useful – a lot of people could do with a chat and I could too, so it will be useful.”

Owen Lloyd’s help could include driving, buying food or making phone calls (Owen Lloyd/PA)

Owen Lloyd, 22, volunteered after seeing the strain his NHS staff friends are under.

He lives a few minutes’ walk away from east London’s ExCeL Centre, currently being transformed into NHS Nightingale, and said: “I’d like to offer any support when that is ready.”

Mr Lloyd said: “Even if I only end up doing one thing through this, I will be proud to say I have assisted the NHS and taken some pressure off our brilliant NHS workers.”

Jacqui Hargrave will be making phone calls to vulnerable people (Jacqui Hargrave/PA)

Jacqui Hargrave, 48, usually writes a popular blog about open water swimming but work is restricted as her family needs to stay home, so she will “be making phone calls to people who are lonely”.

She told PA: “If I can help even one person so they can have something to look forward to during the day then it’s a good thing.”

The Prime Minister praised those who have volunteered during his daily press conference on Wednesday.

Speaking from Number 10, Boris Johnson offered the then-405,000 who had signed up a “special thank you”.

He added: “When we launched the appeal last night, we hoped to get 250,000 volunteers over a few days” and said the volunteers would be “absolutely crucial” in the fight against the spread of the illness.